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China's national government and Beijing city authorities have adopted additional control measures to reduce the negative impact of vehicle emissions on Beijing's air quality. An evaluation of the effectiveness of these measures may provide guidance for future vehicle emission control strategy development. In-use emissions from light-duty gasoline vehicles (LDGVs) were investigated at five sites in Beijing with remote sensing instrumentation. Distance-based mass emission factors were derived with fuel consumption modeled on real world data. The results show that the recently implemented aggressive control strategies are significantly reducing the emissions of on-road vehicles. Older vehicles are contributing substantially to the total fleet emissions. An earlier program to retrofit pre-Euro cars with three-way catalysts produced little emission reduction. The impact of model year and driving conditions on the average mass emission factors indicates that the durability of vehicles emission controls may be inadequate in Beijing. [ABSTRACT FROM AUTHOR]

As the motor vehicle population in China continues to increase at an annual rate of ∼15%, air pollution related to vehicular emissions has become the focus of attention, especially in large cities. There is an urgent need to identify the severity of this pollution in China. Based on an investigation into vehicle service characteristics, this study used a series of driving cycle tests of in-use Chinese motor vehicles for their emission factors in laboratories, which indicated that CO and HC emission factors are 5-10 times higher, and NO[subx] 2-5 times higher, than levels in developed countries. The MOBILE5 model was adapted to the Chinese situation and used to calculate the emission of pollutants from motor vehicles. Results show that vehicle emission is concentrated in major cities, such as Beijing, Guangzhou, Shanghai, and Tianjin. Motor vehicle emissions contribute a significant proportion of pollutants in those cities, with contribution rates of CO and NO[subx] greater than 80% and 40%, respectively, in Beijing and Guangzhou. Urban air quality is far worse than the national ambient air quality standard. In conclusion, although China has a relatively small number of motor vehicles, most of them are concentrated within metropolitan areas, and their emissions are closely related to urban air pollution problems in large cities. [ABSTRACT FROM AUTHOR]

It is important to develop a general model to accurately simulate the air pollution in urban street areas. In this paper, the Operational Street Pollution Model (OSPM) initially developed in Denmark is tested with measured data from a relatively wide and open street in Beijing. Major factors influencing the dispersion, such as emission factors, stationary source emissions, and solar radiation, are analyzed. Results show that the model can reflect the basic dispersion pattern in the street but gives systematically higher concentrations. After modifications to estimate street-level wind speed in the model, performance is obviously improved. [ABSTRACT FROM AUTHOR]

Reports that an instantaneous dust monitor was adopted in the study to take the measurement of traffic dust at urban roadside in Hong Kong to correlate the major factors affecting traffic dust emissions and concentrations. Emission factor models; Exhaust particulate measurement; Reentrainment particulate measurement of traffic dust.

Indium tin oxide (ITO) catalysts with different In/Sn ratios have been prepared by the co-precipitation method. The catalysts were evaluated for methane combustion at different temperatures (673–873 K) with a space velocity of 30 000 h-1. The results showed that methane could be completely oxidized at 873 K with ITO catalysts. Doping an appropriate amount of tin into In2O3 could greatly improve its activity, while the performances of Indium-doped tin oxides were worse than that of SnO2. A significant improvement of the activity was obtained on the catalyst In8Sn2, which contains 80 wt. % of indium oxide and 20 wt. % of tin oxide. Crystal defection and the amount of oxygen vacancy caused by doping were the main factors that would affect catalytic activity of ITO catalysts. The catalytic activity is strongly inhibited by the presence of a large amount of water vapor at the entire temperature range, while only the activity at low temperature (under 823 K) decreased in the presence of sulfur dioxide. By doping Sn into In2O3, its tolerance to SO2 could be enhanced due to the higher resistance of SnO2. [ABSTRACT FROM AUTHOR]

The catalytic removal of NO x under lean conditions is one of the most important targets in catalysis research. The activities of metal oxides, zeolite-based catalysts and noble metal catalysts together with the factors are influencing the selective reduction of NO x with hydrocarbons are reviewed. The reaction mechanisms for the three types of catalysts are briefly discussed. Recent progress in combined catalyst and NO x storage reduction catalysts is also introduced. Finally, future research directions are forecasted. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the protective effect of puerarin against apoptosis of osteoblasts and chondrocytes. Methods: Osteoblast-like MC3T3-E1 cells and chondrocyte ATDC5 were used as cellular models. Dexamethasone (Dex) was used to induce cellular stress. Cell viability was determined with cell counting kit-8 (CCK-8) assay. Cell apoptosis and the level of reactive oxygen species (ROS) were also measured. Changes in ERS markers were measured with quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blotting. Results: Treatment with puerarin reduced cell viability and increased apoptosis, and inhibited the production of ROS. Furthermore, the expression levels of ER stress markers (ATF6, IRE1α, GRP78, XBP1, and eIF2α) were decreased after treatment with puerarin. Conclusion: Puerarin protected MC3T3-E1 and ATDC5 cells from apoptosis via attenuation of the expression levels of ER stress markers. Thus, puerarin may be a potential drug for treatment of ONFH. [ABSTRACT FROM AUTHOR]

Vertical profiles, horizontal profiles and size distribution of airborne particulate matter were measured near major roads in Macao using DustTrak and TEOM monitors. A significant decrease in the concentrations of PM[sub 10], PM[sub 2.5] and PM[sub 1], as the height above the ground increases from 2 to 79 m, was found. At the height of 79 m, the concentrations of PM[sub 10], PM[sub 2.5] and PM[sub 1], decrease to about 60%, 62% and 80% of the maximum occurring at 2m above the ground, respectively. However, the horizontal profiles near another major road revealed there was no significant trend of decrease in concentrations of particulate matter as the distance from the road increases. Over the total measured distance (0-228 m), the maximum decreases of PM[sub 10], PM[sub 2.5] and PM[sub 1] are only 7%, 9% and 10%, of the maximum occurring at 2m from the road, respectively. The daytime averaged PM[sub 2.5] and PM[sub 1] contribute 66-67% and 51-60%, respectively, of the total PM[sub 10] mass after the particle readings by DustTrak were recalibrated by TEOM. It showed that fine particles and submicrometer particles contributed a major part of PM[sub 10] at the roadside in Macao, which is most likely attributed to the combinations of local sources including exhausted particulate matter from vehicles and resuspended fine dust, and secondary particles (sulfate, nitrate and ammonium) of regional scales. [ABSTRACT FROM AUTHOR]

Importance: Electroacupuncture involving the lumbosacral region may be effective for women with stress urinary incontinence (SUI), but evidence is limited.Objective: To assess the effect of electroacupuncture vs sham electroacupuncture for women with SUI.Design, Setting, and Participants: Multicenter, randomized clinical trial conducted at 12 hospitals in China and enrolling 504 women with SUI between October 2013 and May 2015, with data collection completed in December 2015.Interventions: Participants were randomly assigned (1:1) to receive 18 sessions (over 6 weeks) of electroacupuncture involving the lumbosacral region (n = 252) or sham electroacupuncture (n = 252) with no skin penetration on sham acupoints.Main Outcomes and Measures: The primary outcome was change from baseline to week 6 in the amount of urine leakage, measured by the 1-hour pad test. Secondary outcomes included mean 72-hour urinary incontinence episodes measured by a 72-hour bladder diary (72-hour incontinence episodes).Results: Among the 504 randomized participants (mean [SD] age, 55.3 [8.4] years), 482 completed the study. Mean urine leakage at baseline was 18.4 g for the electroacupuncture group and 19.1 g for the sham electroacupuncture group. Mean 72-hour incontinence episodes were 7.9 for the electroacupuncture group and 7.7 for the sham electroacupuncture group. At week 6, the electroacupuncture group had greater decrease in mean urine leakage (-9.9 g) than the sham electroacupuncture group (-2.6 g) with a mean difference of 7.4 g (95% CI, 4.8 to 10.0; P < .001). During some time periods, the change in the mean 72-hour incontinence episodes from baseline was greater with electroacupuncture than sham electroacupuncture with between-group differences of 1.0 episode in weeks 1 to 6 (95% CI, 0.2-1.7; P = .01), 2.0 episodes in weeks 15 to 18 (95% CI, 1.3-2.7; P < .001), and 2.1 episodes in weeks 27 to 30 (95% CI, 1.3-2.8; P < .001). The incidence of treatment-related adverse events was 1.6% in the electroacupuncture group and 2.0% in the sham electroacupuncture group, and all events were classified as mild.Conclusions and Relevance: Among women with stress urinary incontinence, treatment with electroacupuncture involving the lumbosacral region, compared with sham electroacupuncture, resulted in less urine leakage after 6 weeks. Further research is needed to understand long-term efficacy and the mechanism of action of this intervention.Trial Registration: clinicaltrials.gov Identifier: NCT01784172. [ABSTRACT FROM AUTHOR]

Background: Acupuncture has been used for chronic constipation, but evidence for its effectiveness remains scarce.Objective: To determine the efficacy of electroacupuncture (EA) for chronic severe functional constipation (CSFC).Design: Randomized, parallel, sham-controlled trial. (ClinicalTrials.gov: NCT01726504).Setting: 15 hospitals in China.Participants: Patients with CSFC and no serious underlying pathologic cause for constipation.Intervention: 28 sessions of EA at traditional acupoints or sham EA (SA) at nonacupoints over 8 weeks.Measurements: The primary outcome was the change from baseline in mean weekly complete spontaneous bowel movements (CSBMs) during weeks 1 to 8. Participants were followed until week 20.Results: 1075 patients (536 and 539 in the EA and SA groups, respectively) were enrolled. The increase from baseline in mean weekly CSBMs during weeks 1 to 8 was 1.76 (95% CI, 1.61 to 1.89) in the EA group and 0.87 (CI, 0.73 to 0.97) in the SA group (between-group difference, 0.90 [CI, 0.74 to 1.10]; P < 0.001). The change from baseline in mean weekly CSBMs during weeks 9 to 20 was 1.96 (CI, 1.78 to 2.11) in the EA group and 0.89 (CI, 0.69 to 0.95) in the SA group (between-group difference, 1.09 [CI, 0.94 to 1.31]; P < 0.001). The proportion of patients having 3 or more mean weekly CSBMs in the EA group was 31.3% and 37.7% over the treatment and follow-up periods, respectively, compared with 12.1% and 14.1% in the SA group (P < 0.001). Acupuncture-related adverse events during treatment were infrequent in both groups, and all were mild or transient.Limitations: Longer-term follow-up was not assessed. Acupuncturists could not be blinded.Conclusion: Eight weeks of EA increases CSBMs and is safe for the treatment of CSFC. Additional study is warranted to evaluate a longer-term treatment and follow-up.Primary Funding Source: Ministry of Science and Technology of the People's Republic of China through the Twelfth Five-Year National Science and Technology Pillar Program. [ABSTRACT FROM AUTHOR]

Black carbon (BC) emissions from heavy-duty diesel vehicles (HDDVs) are rarely continuously measured using portable emission measurement systems (PEMSs). In this study, we utilize a PEMS to obtain real-world BC emission profiles for 25 HDDVs in China. The average fuel-based BC emissions of HDDVs certified according to Euro II, III, IV, and V standards are 2224 ± 251, 612 ± 740, 453 ± 584, and 152 ± 3 mg kg-1, respectively. Notably, HDDVs adopting mechanical pump engines had significantly higher BC emissions than those equipped with electronic injection engines. Applying the useful features of PEMSs, we can relate instantaneous BC emissions to driving conditions using an operating mode binning methodology, and the average emission rates for Euro II to Euro IV diesel trucks can be constructed. From a macroscopic perspective, we observe that average speed is a significant factor affecting BC emissions and is well correlated with distance-based emissions (R² = 0.71). Therefore, the average fuel-based and distance-based BC emissions on congested roads are 40 and 125% higher than those on freeways. These results should be taken into consideration in future emission inventory studies. [ABSTRACT FROM AUTHOR]

Roadside remote sensing measurement was used to explore the real-world emission status of light duty gasoline vehicles (LDGVs) and motorcycles in Macao. Both fuel-based and distance-based emission factors were derived using the mass balance method. The emission concentration profile of LDGVs illustrated the benefits of tightening emission standards at the source country or region of import. The distance-based emission factors for CO, HC and NOx of LDGVs registered before 2000 were 8.00, 1.04 and 1.36 g/km, respectively. The distance-based emission factors for CO, HC and NOx of LDGVs registered in or after 2000 were 1.16, 0.15 and 0.18 g/km, respectively. The fuel-based CO emission factors of light duty motorcycles (LDMCs) and heavy duty motorcycles (HDMCs) registered before 2000 were about 10 times higher than those of LDGVs of the same age group. As the emissions of LDGVs decreased more quickly after 2000, the gap widens for newer vehicles. The distance-based HC emission factors of LDMCs and HDMCs registered before 2000 were 4.81 and 2.91 g/km, respectively. The distance-based HC emission factors of LDMCs and HDMCs registered in or after 2000 were 3.52 and 0.93 g/km, respectively. The poor emission performance of motorcycles and their larger share in the traffic flow will cause them to be the major contributor to traffic CO and HC emissions. LDMCs, especially two-stroke models, should be the priority for vehicle emission control efforts in Macao. [ABSTRACT FROM AUTHOR]

Application of Fe-zeolites for urea-SCR of NOx in diesel engine is limited by catalyst deactivation with hydrocarbons (HCs). In this work, a series of Fe-zeolite catalysts (Fe-MOR, Fe-ZSM-5, and Fe-BEA) was prepared by ion exchange method, and their catalytic activity with or without propene for selective catalytic reduction of NOx with ammonia (NH3-SCR) was investigated. Results showed that these Fe-zeolites were relatively active without propene in the test temperature range (150-550 °C); however, all of the catalytic activity was suppressed in the presence of propene. Fe-MOR kept relatively higher activity with almost 80% NOx conversion even after propene coking at 350 °C, and 38% for Fe-BEA and 24% for Fe-ZSM-5 at 350 °C, respectively. It was found that the pore structures of Fe-zeolite catalysts were one of the main factors for coke formation. As compared to ZSM-5 and HBEA, MOR zeolite has a one-dimensional structure for propene diffusion, relatively lower acidity, and is not susceptible to deactivation. Nitrogenated organic compounds (e.g., isocyanate) were observed on the Fe-zeolite catalyst surface. The site blockage was mainly on Fe3+ sites, on which NO was activated and oxidized. Furthermore, a novel fully formulated Fe-BEA monolith catalyst coating modified with MOR was designed and tested, the deactivation due to propene poisoning was clearly reduced, and the NOx conversion reached 90% after 700 ppm C3H6 exposure at 500 °C. [ABSTRACT FROM AUTHOR]

Beijing, the capital of China, has experienced rapid motorization since 1990; a trend that is likely to continue. The growth in vehicles and the corresponding emissions create challenges to improving the urban air quality. In an effort to reduce the impact of vehicle emissions on urban air quality, Beijing has adopted a number of vehicle emission control strategies and policies since the mid 1990s. These are classified into seven categories: (1) emission control on new vehicles; (2) emission control on in-use vehicles; (3) fuel quality improvements; (4) alternative-fuel and advanced vehicles; (5) economic policies; (6) public transport; and (7) temporal traffic control measures. Many have proven to be successful, such as the Euro emission standards, unleaded gasoline and low sulfur fuel, temporal traffic control measures during the Beijing Olympic Games, etc. Some, however, have been failures, such as the gasoline-to-LPG taxi retrofit program. Thanks to the emission standards for new vehicles as well as other controls, the fleet-average emission rates of CO, HC, NOX, and PM10 by each major vehicle category are decreasing over time. For example, gasoline cars decreased fleet-average emission factors by 12.5% for CO, 10.0% for HC, 5.8% for NOX, and 13.0% for PM10 annually since 1995, and such a trend is likely to continue. Total emissions for Beijing's vehicle fleet increased from 1995 to 1998. However, they show a clear and steady decrease between 1999 and 2009. In 2009, total emissions of CO, HC, NOX, and PM10 were 845000 t, 121000 t, 84000 t, and 3700 t, respectively; with reductions of 47%, 49%, 47%, and 42%, relative to 1998. Beijing has been considered a pioneer in controlling vehicle emissions within China, similar to the role of California to the U.S. The continued rapid growth of vehicles, however, is challenging Beijing's policy-makers. [ABSTRACT FROM AUTHOR]

Air quality was a vital concern for the Beijing Olympic Games in 2008. To strictly control air pollutant emissions and ensure good air quality for the Games, Beijing municipal government announced an "Air Quality Guarantee Plan for the 29th Olympics in Beijing". In order to evaluate the effectiveness of the guarantee plan, this study analyzed the air pollutant emission reductions during the 29th Olympiad in Beijing. In June 2008, daily emissions of SO2, NOx, PM10, and NMVOC in Beijing were 103.9 t, 428.5 t, 362.7 t, and 890.0 t, respectively. During the Olympic Games, the daily emissions of SO2, NOx, PM10, and NMVOC in Beijing were reduced to 61.6 t, 229.1 t, 164.3 t, and 381.8 t -41%, 47%, 55%, and 57% lower than June 2008 emission levels. Closing facilities producing construction materials reduced the sector's SO2 emissions by 85%. Emission control measures for mobile sources, including high-emitting vehicle restrictions, government vehicle use controls, and alternate day driving rules for Beijing's 3.3 million private cars, reduced mobile source NOx and NMVOC by 46% and 57%, respectively. Prohibitions on building construction reduced the sector's PM10 emissions by approximately 90% or total PM10 by 35%. NMVOC reductions came mainly from mobile source and fugitive emission reductions. Based on the emission inventories developed in this study, the CMAQ model was used to simulate Beijing's ambient air quality during the Olympic Games. The model results accurately reflect the environmental monitoring data providing evidence that the emission inventories in this study are reasonably accurate and quantitatively reflect the emission changes attributable to air pollution control measures taken during the 29th Olympic Games in 2008. [ABSTRACT FROM AUTHOR]

The Ba1 - xSrxTi0.94Sn0.06O3 (BSTS) ceramics were prepared by solid-state reaction method. The microstructure was studied by scanning electron microscopy. The dielectric constant and loss as a function of temperature and external bias electric field were investigated. As strontium concentration increasing, the peak permittivity decreases. The Curie temperature decreases at an average rate of 2.86°C/mol% as the concentration of Sr2 + increases in the system of BSxTS0.06. The maximum tunability of 63.5% at applied electric field of 6 kV/cm was obtained with the composition of Ba0.8Sr0.2Ti0.94Sn0.06O3. [ABSTRACT FROM AUTHOR]

Selective catalytic reduction of NO with propene was investigated over In2O3/Al2O3 catalysts prepared by three methods, namely, a single sol-gel (SG), impregnation (IM), and co-precipitation method (CP). The catalysts were characterized by means of BET, XRD, XPS, and TPD. The maximum NO conversion over In2O3/Al2 O3 prepared by sol-gel method was 95% at 400 °C in the absence of H2O, and the activity decreased slightly in the presence of H2O, and it was still 76% even in the presence of H2O and SO2. Although the retarding effect of SO2 on the activity was observed for the three catalysts, In2O3/Al2O3 (SG) showed relatively high activity. It is found that the high surface area and low average pore diameter are important to the catalytic activity, and the strong interaction between indium and alumina for In2O3/Al2O3 catalyst prepared by sol-gel method may be the reason of high activity for NO reduction. The reaction and surface studies showed that NO and partially oxidized hydrocarbons (RCOO− species) are mainly intermediates, and the oxidation C3H6 to RCOO− species maybe the key reaction process in the SCR of NO with C3H6. [ABSTRACT FROM AUTHOR]

Addresses anthropogenic emissions of non-methane volatile organic compounds (NMVOC) in China at provincial level for the period 1990 to 2020. NMVOC emission factors for stationary fuel-related source categories; Important sources of NMVOC emissions; Assumed changes in the major activity parameters used in the estimation of NMVOC emissions for China.

Examines the application of the long-range transport model for the control of acid rain and sulfur dioxide pollution in China. Increase of sulfur dioxide deposition; Relationship between deposition and emission process; Sensitivity of the model to variations of parameters.